Filter apparatus



FIG. 1 is a perspective view of the claimed filter apparatus.

FIG. 2 is a side view of the claimed apparatus showing volumetric markings.

FIG. 3 is a side view of the claimed apparatus.

FIG. 4 is a top view of the filter apparatus; and,

FIG. 5 is a bottom plan view of the filter apparatus.

The broken line showing in FIGS. 4 and 5 is included for the purpose of illustrating and forms no part of the claimed design. 

The ornamental design for a filter apparatus, as shown and described. 